add methods for creating a vectorial clip from a rectangular cli and creating a drawing from a rectangular clip
fix bad function signature use
ASSDrawing: add method for drawing a rectangle
ASSBase:coerce(): make assertion a little more safe
add option to inverse tag name match when filtering a tag list
tag cleaning: add option to supply a table of tags to keep that would otherwise be removed if they matched the style defaults for the line.
Defaults to the \pos tag, which may affect collision when there is more than one positionless line at a time
extend override->internal tag names mapping to also take tables of override tags
Common: add function for diffing two numerically indexed tables (only values are compared, not keys)
Common: add optional exclusion parameter to table.keys()
reformat tag database
add tag sorting for ASSTagList -> ASSLineTagSection
Tag Lists: correctly handle \1a... tags that are overridden by \alpha
introduce new helper function for getting tag names by matching the properties of the tags with a user-supplied table
Common: optimize table.trimArray